#include <iostream>
#include <fstream>
#include <iomanip>
#include <cstdlib>
#include <cstring>

using namespace std;

struct student_rec { long id;
    string last, first;
};

struct enroll_rec  { long id, crn;
    int  year, grade;
};

struct section_rec { long crn;
    int  year;
    string dept;
    int  cnum, snum;
    string building, room;
};

struct course_rec { string dept;
    int num;
    string name;
};

struct studentWithGrade {
    long id;
    string last, first;
    int grade;
};

bool read_student(ifstream &f, student_rec &s);
bool read_enroll (ifstream &f, enroll_rec  &e);
bool read_section(ifstream &f, section_rec &s);
bool read_course (ifstream &f, course_rec  &c);

bool find_student(student_rec &student, long id);
bool find_section(section_rec &section, int year, string dept, int cnum, int snum);
int find_enroll(enroll_rec &enroll, long CRN, studentWithGrade *students);

int main()
{
    // Start in section, use Year, DepCode, CourseNo- take the CRN number
    // Use CRN number to find student ID, and Grade in enroll
    // Use Student ID to find first and Last name

    student_rec student;
    section_rec section;
    enroll_rec enroll;

    int n = 100;


    string input;

    //cout<< "jfilue" << endl;
    //cin>> input;

    string dept= "CSCI";
    int year= 2014, cnum= 275, snum= 20;

    if (!find_section(section, year, dept, cnum, snum)){
        cout << "Student not found!" << endl;
    }

    studentWithGrade *students;
    students = new studentWithGrade[n];

    int numStudents = find_enroll(enroll, section.crn, students);

    if (numStudents == 0){
        cout << "Student not found!" << endl;
    }

    for (int i=0; i<numStudents; i++)
    {

        if (!find_student(student, students[i].id)) {
            cout << "Student not found!" << endl;
        }

        students[i].first= student.first;
        students[i].last= student.last;
    }


   for (int i=0; i<numStudents; i++)
   {
       cout<< students[i].first << setw(15) << students[i].last << setw(15) << students[i].grade << setw(15) <<endl;
   }



    return 0;
}

bool find_section(section_rec &section, int year, string dept, int cnum, int snum)
{
    ifstream file("section.txt");

    if (!file) {
        cout << "Secton file not found!" << endl;
        return false;
    }

    while (read_section(file, section))
    {
        if (section.year == year && section.dept == dept && section.cnum == cnum && section.snum == snum)
        {
            return true;
        }
    }

    file.close();
    return false;
}

int find_enroll(enroll_rec &enroll, long CRN, studentWithGrade *students)
{
    ifstream file("enroll.txt");

    if (!file) {
        cout << "Secton file not found!" << endl;
        return false;
    }

    int count=0;

    while (read_enroll(file, enroll)) {
        if (enroll.crn == CRN)
        {
            students[count++].id= enroll.id;
            students[count++].grade= enroll.grade;
        }
    }

    file.close();
    return count;

}


bool find_student(student_rec &student, long id)
{
    ifstream file("student.txt");

    if (!file) {
        cout << "Student file not found!" << endl;
        return false;
    }

    while (read_student(file, student)) {
        if (student.id == id) return true;
    }

    file.close();
    return false;
}

bool read_student(ifstream &f, student_rec &s)
{
    char comma;
    if (f.eof()) return false;
    f >> s.id >> comma;
    getline(f, s.last, ',');
    getline(f, s.first);
    return true;
}

bool read_enroll(ifstream &f, enroll_rec &e)
{
    char comma, str[10];
    if (f.eof()) return false;
    f >> e.id >> comma >> e.crn >> comma >> e.year;
    f.getline(str, 10);
    if (strlen(str) > 1) e.grade = atoi(&str[1]);
    else e.grade = -1;
    return true;
}

bool read_section(ifstream &f, section_rec &s)
{
    char comma;
    if (f.eof()) return false;
    f >> s.crn >> comma >> s.year >> comma;
    getline(f, s.dept, ',');
    f >> s.cnum >> comma >> s.snum >> comma;
    if (comma == ',') {
        getline(f, s.building, ',');
        getline(f, s.room);
    } else {
        s.building[0] = s.room[0] = '\0';
    }
    return true;
}

bool read_course(ifstream &f, course_rec &c)
{
    char comma;
    getline(f, c.dept, ',');
    if (f.eof()) return false;
    f >> c.num >> comma;
    getline(f, c.name);
    return true;
}